1. Field of the Invention
The present invention relates to a changer-type disk device capable of reproducing and/or recording information in a CD (compact disk) or a DVD (digital versatile disk) and accommodating a plurality of disks in the device, and more particularly to a slot-in changer-type disk device for automatically transferring a disk inserted through a loading slot.
2. Description of the Related Art
Automobile changer-type disk devices often use a slot-in system for automatically transferring a disk inserted through a loading slot with a disk transfer mechanism. Such changer-type disk devices include a drive unit for reproducing and/or recording information by optical pickup by driving the rotation of the disk and a disk storage section capable of storing a plurality of disks side-by-side in the axial direction of the disks. The drive unit is moved back and forth between the drive position and the retracted position by a drive activating mechanism. One of a plurality of disks held in the disk storage section is selectively taken out in the drive position, and rotated by the drive unit.
Changer-type disk devices are well known in which a plurality of stockers is arranged so as to be freely moved up and down as the disk storage section. Such a disk storage section includes arch-shaped stockers each capable of holding the circumferential edge of a disk about halfway around and a plurality of lead screws each having a spiral groove with an irregular pitch. The lead screws are inserted and screwed into the plurality of stockers, arranged in layers, and are rotated synchronously, thereby allowing the stockers (each holding a disk) to be moved up and down in the axial direction of the lead screws.
For example, when a disk inserted into the device is held in a desired stocker, the stocker is positioned at the same height as the transfer path of the disk. Thereafter, the disk is carried to the back of the device by the disk transfer mechanism, so that the disk can be held by the inner periphery of the corresponding stocker. When a selected disk held in a desired stocker is taken out to a play position, the stocker is positioned at the same height as the transfer path of the disk. Thereafter, the selected disk held in the stocker is transferred toward the front of the device, and the selected disk can be removed from the inner periphery of the stocker and clamped in the drive unit. The inner periphery of the stocker has an arch-shaped lock groove into which the circumferential edge of the disk can be inserted about halfway around, by which the disk can be held in a state in which the disk is locked in position in its axial and radial directions.
Because the conventional changer-type disk device described above is constructed such that the stocker is moved up and down while the drive unit is positioned in its retracted position, and the drive unit can overlap with the disk held in the stocker in the drive position, the space in the device can be used effectively, thus reducing the size. However, the stocker is moved up and down while being fitted in the spiral groove of the lead screw, so that a minute clearance is required between the stocker and the spiral groove. Also, since the disk held in the stocker can vary in its manufacturing dimensions, the inside diameter of the stocker-holding groove must be set to a dimension at which a disk of a possible maximum diameter can be inserted. Furthermore, in the slot-in changer-type disk device, since an obstacle cannot intrude on the disk-transfer path from the loading slot to the stocker, the stocker-holding groove can only be provided about halfway around the disk (about 180°). Therefore, it is difficult for the stocker to hold the disk securely. For those reasons, if external vibrations from the vehicle are applied to the changer-type disk device when a desired selected disk is taken out of the stocker and driven, the other waiting disks remaining in the stockers may vibrate to cause a rattle noise. Particularly, when music recorded in the disk is played back, such a rattle noise is extremely grating to the listener.